Jeremiah calls YHWH the fountain of living waters and condemns Israel for forsaking him.
Jeremiah 2:13; Jeremiah 17:13; Isaiah 55:1 are central backgrounds.
Jesus does not merely direct the woman to God's fountain; he says the living water is his to give.
The claim anticipates John 7, where Jesus again summons the thirsty to come to him and John identifies the gift with the Spirit.
The woman progressively recognizes Jesus' significance and brings others to him.